<!DOCTYPE html>
<html>
<head>
    <title>Iframe Example</title>
</head>
<body>
    <input type='text' name='level1-textfield1' placeholder='Level 1 Text Field 1'>
    <input type='text' name='level1-textfield2' placeholder='Level 1 Text Field 2'>
    <iframe srcdoc="
        <!DOCTYPE html>
        <html>
        <head>
            <title>Iframe Level 2.1</title>
        </head>
        <body>
            <h2>Iframe Level 2.1</h2>
            <input type='text' name='level2_1-textfield1' placeholder='Level 2.1 Text Field 1'>
            <input type='text' name='level2_1-textfield2' placeholder='Level 2.1 Text Field 2'>
        </body>
        </html>
    "></iframe>
    <iframe srcdoc="
        <!DOCTYPE html>
        <html>
        <head>
            <title>Iframe Level 2.2</title>
        </head>
        <body>
            <h2>Iframe Level 2.2</h2>
            <input type='text' name='level2_2-textfield1' placeholder='Level 2.2 Text Field 1'>
            <input type='text' name='level2_2-textfield2' placeholder='Level 2.2 Text Field 2'>
        </body>
        </html>
    "></iframe>

</body>
</html>
